[Analysis of clinical characteristics of 854 patients with thyroid cancer]

Objective:The aim of this study is to summarize and analyze the clinical features of thyroid cancer surgery patients, and provide information and guidance for clinical diagnosis and treatment. Method:The medical records of 854 patients with thyroid cancer who met the inclusion criteria from January 2013 to December 2018 were collected from the hospital's medical record system. Patients were grouped by age group and their stratified studies were performed on age, gender, pathological type, and cervical lymph node metastasis. Result:The total number of patients with thyroid cancer surgery in 2013-2018 showed an increasing trend. There was no significant difference in the age composition of thyroid cancer patients between different years （P>0.05）, but the age of 20-54 years old gradually increased with age, and reached a peak at 50-54 years old, then gradually decreased. There was no significant difference in gender composition between patients with thyroid cancer surgery in 2013-2018 （P>0.05）, but in 40-44 years old, the prevalence of women in the 50-54 age group was higher than that in men （P<0.05）, The prevalence of men in the 70-74 age group was higher than that in women （P<0.05）, and the peak period of both was 50-54 years old. Papillary carcinoma accounted for a high proportion （96.8%） in the pathological types of thyroid cancer surgery patients in 2013-2018, and the incidence of women in the 40-44 age group was higher than that in men（P<0.01）, in the 70-74 age range. The incidence was higher than that of women （P<0.01）. The incidence of follicular carcinoma （1%） was higher in men than in women （P<0.05）. The incidence of lymph node metastasis in women with thyroid cancer was lower than that in men （P<0.05）. Conclusion:The incidence of thyroid cancer in different age groups has its own characteristics, and prevention and control measures should be formulated according to age groups.

MiRNA-500a-3p inhibits cell proliferation and invasion by targeting lymphocyte antigen 6 complex locus K (LY6K) in human non-small cell lung cancer

LY6K (lymphocyte antigen 6 complex locus K) is an anti-gene in non-small cell lung cancer (NSCLC) and miR-500a-3p promotes the progression of cancers. Evidence shows that the increase of miR-500a-3p caused LY6K to be suppressed. Here we hypothesized that miR-500a-3p may take part in the progression of NSCLC through targeting LY6K. miR-500a-3p expression levels in NSCLC specimens and cell lines were detected by quantitative real-time PCR (qRT-PCR). The mRNA and protein expression levels of LY6K in NSCLC specimens and cell lines were examined by qRT-PCR, immunohistochemistry and western blotting. Dual-luciferase reporter assay was carried out to assess miR-500a-3p binding to LY6K gene. The functions of miR-500a-3p and LY6K in proliferation/invasion and lung metastasis formation were assessed by CCK8, Transwell assay and subcutaneous tumor model in nude mice, respectively. Statistical analysis was performed to explore the clinical correlation between miR-500a-3p/LY6K expression and clinicopathological features. miR-500a-3p was substantially decreased in NSCLC tissues and cell lines. LY6K protein and mRNA level expressions were increased in NSCLC patients. Clinical analysis indicated that miR-500a-3p and LY6K were related to tumor differentiation, lymph node metastasis and TNM staging in NSCLC patients. MiR-500a-3p suppresses cell proliferation, invasion and metastasis formation in vivo by targeting the LY6K. miR-500a-3p acts as a tumor suppressor in NSCLC partially via down-regulation of LY6K expression and for NSCLC intervention and suggests a potential therapeutic target for NSCLC intervention.

Determination of guidance levels of dose for diagnostic radiography in Taiwan

The International Atomic Energy Agency has recommended guidance levels of dose for diagnostic radiography for a typical adult patient. These levels were intended to act as thresholds to trigger investigations or corrective actions in ensuring optimized protection of patients and maintaining appropriate levels of good practice. Since guidance levels should be derived from wide scale surveys of exposure factors performed in individual hospitals, a national survey was conducted recently in Taiwan to collect these factors for the most frequent radiographic procedures. A total of 276 completed questionnaires were received and analyzed. In the questionnaire, respondents were asked to check those projections that were routinely performed in their department and to report machine data, patient data, output measurements, and technical factors including kVp, mAs, focus-to-film distance, table-to-film distance, aluminum filtration, and focal spot size. Based on the survey data, entrance skin exposures in air, i.e., free air exposures at the point of intersection of the x-ray central beam with the entrance surface of the patient, were estimated using the RADCOMP program. Entrance surface doses to air and tissue with backscatter were then evaluated by the application of the exposure-dose conversion factor and the backscatter factor obtained from TLD measurements and Monte Carlo simulations. Guidance levels were determined from survey results on the entrance surface dose based on optimization considerations involving the cost-effectiveness analysis. Except for chest PA and LAT and skull LAT procedures, all guidance levels derived in this work are less than those recommended by the International Atomic Energy Agency. Survey data and guidance levels were provided to the national authorities to help them develop quality control and radiation protection programs for medical exposures.